The impact of preoperative kidney replacement therapy on kidney outcome and survival in patients with left ventricular assist device

Abstract

Left ventricular assist device (LVAD) has been highlighted as a new treatment option in the end-stage heart failure (HF). Kidney outcome after LVAD in severe cardiorenal syndrome (CRS) patients requiring kidney replacement therapy (KRT) is unclear. We investigated the impact of preoperative KRT on kidney function and survival in LVAD patients with severe CRS. A total of 50 patients followed up for at least 1 year after LVAD implantation was analyzed. The primary outcomes were estimated glomerular filtration rate and survival rate. Patients were divided into two groups depending on in-hospital KRT before LVAD implantation: the control group (n = 33) and the KRT group (n = 17). Postoperative KRT was performed for 76.5% of patients in the KRT group, and all of them discontinued KRT before discharge. There were no statistically significant differences in the degree of eGFR decline in survivors according to preoperative KRT. Although there were no statistically significant differences in the degree of eGFR decline in survivors regardless of preoperative KRT, old age (β -0.94, p < 0.01), preexisting chronic kidney disease (β -21.89, p < 0.01), and high serum creatinine (β -13.95, p < 0.01) were identified as independent predictors of post-LVAD eGFR decline. Mortality rate was higher, and more patients progressed to end-stage kidney disease in KRT group than control group. However, LVAD still can be considered as the treatment option in end-stage HF patients with severe CRS requiring KRT, especially in those with young age and previous normal kidney function.

Keywords: Cardiorenal syndrome; heart failure; kidney function; left ventricular assist device.

Figure 1.

Flowchart of enrolled patients. A total of 50 patients were included in our study. Patients were divided into two groups depending on preoperative KRT: the control (non-KRT) group (n = 33) and the KRT group (n = 17). Analysis for baseline characteristics and survival was performed. Linear fixed effects analysis regarding post-LVAD eGFR was performed after excluding patients who expired before 1 year after LVAD implantation (n = 2 in the control group and n = 3 in the KRT group).

Figure 2.

Changes in eGFR depending on preoperative KRT. In all patients, eGFR was significantly improved after LVAD implantation. At each time point up to 3 years after LVAD implantation, eGFR of the KRT group was lower than that of the control group. However, there was no statistical difference in the degree of eGFR decline over postoperative time between the two groups (p = 0.57). *p < 0.05 compared with the control group at each time point. The eGFR are presented as mean ± SD at the time point.

Figure 3.

Kaplan–Meier curves for post-LVAD ESKD during the follow-up period after LVAD implantation. Kaplan–Meier curves showed a significant difference in the cumulative prevalence of post-LVAD ESKD between the control and KRT groups (log rank p = 0.008).

Figure 4.

Kaplan–Meier curves for survival during the follow-up period after LVAD implantation. Kaplan–Meier curves showed no significant difference in the cumulative survival between the control and KRT groups (log rank p = 0.16).

Figure 5.

Kaplan–Meier survival curves according to the initiation timing of KRT. Kaplan–Meier curves showed no significant difference in the cumulative survival among the no KRT, preoperative KRT, and postoperative KRT groups (log rank p = 0.35).